Closing price of common stock.

No definition available.

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- Definition

Number of stock incentive plans.

+ References

No definition available.

+ Details

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- Definition

Period vested for restricted stock.

+ References

No definition available.

+ Details

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- Definition

Share based compensation arrangement by share based payment award equity instruments other than options performance shares net of forfeitures.

+ References

No definition available.

+ Details

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- Definition

Share based compensation arrangement by share based payment award equity instruments other than options performance shares payout achievement.

+ References

No definition available.

+ Details

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- Definition

Share based compensation arrangement by share based payment award equity instruments other than options performance shares payout range maximum.

+ References

No definition available.

+ Details

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- Definition

Share based compensation arrangement by share based payment award equity instruments other than options performance shares payout range minimum.

+ References

No definition available.

+ Details

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- Definition

Share based compensation arrangement by share based payment award expiration period.

+ References

No definition available.

+ Details

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- Details

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- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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Stock-Based Compensation Plans (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Incentive	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested	$ 1.8
Weighted-average period over which cost is expected to be recognized	3 years
Stock-Based Compensation Plans (Textual) [Abstract]
Number of stock incentive plans	2
Shares available for grant under the stock incentive plans	5,116,163
Expiration period of stock options from date of grant	10 years
Weighted-average fair value for option granted	$ 12.26	$ 11.29	$ 5.45
Closing price of common stock	35.30
Pay-out ranges, Minimum	0.00%
Pay-out ranges, Maximum	150.00%
Pay-out achievement	92.50%	146.00%	150.00%
Stock forfeitures		14,563
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period vested for option grants	5 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period vested for option grants	3 years
Restricted stock and performance shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested	$ 9.7
Weighted-average period over which cost is expected to be recognized	1 year 8 months 12 days
Period vested for restricted stock	3 years